We'll be having yudansha exams tonight including at least one sandan and one yondan exam. Of the ones I've seen of these, our chief instructor will ask the person to usually do one or two "basic" techniques from each attack and then call out "Free" (meaning go into freestyle/jiyuwaza). From what I've seen of these, the techniques are not planned out by nage. (Also, we don't get to choose our uke during these tests; whoever jumps up for you gets to be uke.)